Adding and subtracting machine.



T. 1. WAVRUNEK.

ADDING AND SUBTRACTING MACHINE.

APPLICATION FILED NOV. 2I. 19I7- Patented Feb. 18, 1919.

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ADDING AND SUBTRACTING MACHINE.

APHICATION HL'ED NUV.2I. 1911..

1 ,294,853. Patented Feb, 18, 1919.

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a g WITNESSES j INVENTOH THOMAS J. 'WAVRUNEK, OF SHAWANO, WISCONSIN.

ADDING AND SUTBTRACTING MAGHINE.

' To all whom it may concern:

Be it known that I,THoMAs J. WAvRU- NEK, a citizen of the United States, and a resident of Shawano, in the county of Sha- Wano and State of Wisconsin, have invented a new and Improved Adding and Subtracting Machine, of which the following is a full, clear, and exact description.

This invention relates to calculating machines and deals more particularly with ma-' chines of that type including a plurality of number-carrying wheels and an operating key associated with each Wheel for performing the necessary movements to add or subtract.

The invention has for its general objects to improve and simplify the construction and operation of apparatus of this character so as to be reliable and efiicient in use, comparatively simple and V inexpensive to manufacture, and so designed that additions or subtractions can be performed by the same keys by reversing the order of manipulating the keys in adding or subtracting; that is to say, in adding a number more than ten the keys are operated from left to right, and in subtracting a number two digits or inpre the keys are operated from right to A more specific object of the invention is the provision of a calculating machine in which the number-carrying wheels have each a row of numbers for adding and subtracting, the numbers reading up from zero to nine, and if desired the wheels may be of such diameter as to have a plurality of groupsor series of these numbers, and the operating key for each wheel has a pawl and ratchet means for moving the wheel in one direction with the key, and between adjacent wheels is provided a novel transfer means for transferring from a lower to a higher denomination, this means being of such a design that the key for the wheel of higher denomination will be raised one step by the wheel of lower denomination when the same has made one revolution, so that it is necessary'to again operate this raised key to complete the calculation and turn the keys to normal or' zero position.

With such objects in view, and others which will appear as the description proceeds, the invention comprises various novel features of construction and arrangement of parts which will be set forth with particu- Specification of Letters Patent.

Application file'd'November 21, 1917. Serial No. 203,128.

I ber wheels.

' traction column.

Patented Feb. 18, 1919.

larity in the following description and claims appended hereto.

In the accompanying drawings, which illustrate one embodiment of the invention and wherein similar characters of reference lndlcate corresponding parts in all the views, I,

Fig. 1 is a plan view of the machine;

Fig. 2 is a vertical section on the line 2i2., Fig. 1, showing the parts in. normal position;

Fig. 3 is a similar view showing a key be- 7 ing raised one step for carrying over a calculation into the tens, hundreds or thousands, the normal position of the key being shown by full lines and its raised position by dotted lines;

Fig. 4: is a fragmentary sectional view on the line l4, Fig. 3, to show the number wheels, keys and tenths carrying-over de vice;

Fig. 5 is a front view of the machine; and

Fig. 6 is a face view of one of the number wheels drawn on a reduced scale.

Referring to the drawing, A designates a casing of suitable construction which has a portion 1 of its front curved onan arc of a circle, and in this portion are vertical slots 2, and an aperture 3 at the left of each slot. and in the slots swing the keys or the addition and subtraction calculations, 7

and each line may have a plurality of series of numbers from zero to nine; hence, in the illustration each wheel has three series of ten numbers. The wheels are mounted on a horizontal shaft 6 in such position that the peripheries will be exposed through the openings 3 of the casing. On the casing are two series of numbers 4 and 5 for the addition and subtraction calculations, the addition numbers reading up from one as they do on the number wheels, and the subtraction numbers reading from onedown to correspond with the numbers on the num's In other words, as shown in Fig. 5",one is at the bottom of'the addition column and nine at the bottom of the sub- On the right side of each number wheel are pins or ratchet teeth 7, there being one for each number on the periphery of the number wheel, or, in the present instance, there are thirty ratchet teeth on each wheel. The key B is at the right side of its associated wheel and isprovided with a springpressed pawl 8, which is disposed within the circle of ratchet pins 7 and has its lower end engageable with the said pins. Thus, by moving a. key upwardly from the full. to the dotted-line position, Fig. '2, the pawl clicks over the ratchet teeth or pins 7, but when the lever is moved downwardly from its raised position the lower end of the pawl engages one of the pins and causes the number wheel to turn with the key when it is depressed. A hold-back pawl 9 cooperates with the .ratchet pins to prevent the number wheel from turning with the key as the latter is raised. The pawls 9 are fulcrumed on a bar 10 mounted in the bottom of the casing, and an l..-shaped spring 11 operates on the holdback pawl to yieldingly maintain the same in holding position. On the forward end 12 of each hold-back paw-1 9 is an upwardly-em.

tending finger 13 which extends out of the casing A and forms a stop for the key B when the latter is pressed downwardly to zero position. The hold-back pawl stops the wheel in its proper position when the key is depressed, since the key throws the rear end of the pawl upwardlyto engage between two of the teeth 7 and thereby prevent the wheel from over-traveling, due to momentum. In other words, the pawl 9 performs the function of a brake during forward travel of the wheel and of a stop for pre-- venting the rearward travel of the wheel with the'raising of the key.

Between adjacent number wheels is a tenths carrying-over device which comprises a lever 14 fulcrumed at 15 in the rear of the casingand extending upwardly between the number wheels, and on the upper end of the leverispa curved extremity 16 terminating in a hOOK 17 which engages under the correspondin key B. The extremity 16 rests on the sha t 6, or, more properly, the spacing.

sleeve 18 between adjacent number wheels, and in this position the hook 17 is in close proximity to or engaged with the under edge of the key B, asclearly shown in Fig. 3. Obviously, if the lever 14: is raised, the key B will move with it, and this occurs when a number wheel of lower value moves ten steps. The movement of the lever 14 is effected by any one of three pins 19 on the left face of each number wheel. The pin 19 engages an offset tooth 20 on the lever 1d, the tooth 20 being so designed that the pin 19 will. wipe past'the tooth 20 after ralsing the lever 14 far enough to lift the key B one step or the distance between two adjacent ratchet teeth. This operation will be clear from Fig. 3, where the pin 1 9 has moved from the position a to the position Z), and in doing so newness it has raisedi-the lever 14. from the full to the dotted line position, and this lever has correspondingly raised. the key B one step.

Normally the keys are in the position shown in Fig. 5, with. the zeros of the number wheels showing through the view openings 3 in the casing. Let it be assumed that the two numbers 7 42 and 281 are to be added. The first three keys to the-right are raised respectively to the numbers 7, 1 and 2 on the addition columns 4; of the casing. The levers are then depressed one at a time, beginning with the lever at the left and endingat the.

right. The three levers areagain raised to the numbers 2, S and 1, respectively, and depressed in the same order as before and .one at a time. During this operation the lever 1a associated with the second or tenths wheel causes the third key, or the first key to the left that was operated, to be raised one step, so that this key must be further depressed, which causes the third lever is to raise the fourth key one step, so that when this fourth key is depressed the operation will be completed, and on the machine will be registered the total of 1023.

In subtracting it is merely necessary to raise the key to the number in the rightlxand 'colum 1, headed Sub, that. is to be subtracted,'. and then depress the lever. to zero position. For instance, if it is desired to subtract one frOm live, the key will be raised to the number 1 and then. the key depressed, when 4; will be exposed at the view opening 8. If seven is to be subtracted from eight, the key is raised to the numbe'r 7 and'depressed, when the number 1 will appear at the opening 3.

From the foregoing description taken in connection with the accompanying drawings, the advantages of the construction and method ofoperation will be readily understood by those skilled in the art to which the invention appertains, and while I have described the principle of operation, together with the apparatus which I now consider to be the best embodiment thereof, I desire to have it understood that the apparatus shown is merely illustrative and that such changes may be made when desired as fall within the scope of the appended claims.

Having thus described my invention, I claim as new and desire to secure by Letters Patent: Y

1. A calculating machine comprising a casing having pairs of columns of numbers, the numbers of one column reading reversely to the numbers of the associated column, a key movable along each pair of columns, a number-wheeloperated by each key and having-numbers from .zero to nine, and a tenths-carrying-over device between a wheel of lower value and the key for the next higher value wheel and having means engaged by the wheel of lower value once of two sets of numbers from zero to nlne,

and one set reading reversely to the other 'for addition and subtraction respectively, a number bearing wheel for each group of numbersfa key for operating each wheel,

and a tenths carrying-over device between a wheel of lower value and the key for the next higher value wheel, whereby such key is moved forwardly one unit and must be manually actuated to complete the calculation, said device including a member engaging the key when the latter is in normal position, and means on the adjacent wheel for engaging and. wiping by the member when the said wheel has moved ten units.

3. A calculating machine comprising a plurality .of groups of number columns of ten addition numbers and ten subtraction num bers reading oppositely to the addition numbers,"a wheel having numbers from zero to nine, 'a key for each wheel, a ratchet and pawl mechanism between the key and ad a-v cent wheel, a lever normally engaglng each key and adapted to remain in normal position while the key is manually operated, and

-means on each wheel for engaging the lever of the key of the next wheel to move such key one step when the number wheel moves ten steps.

4. A calculating machinecomprlsing a plurality of number-carryingwheels, a shaft supporting the wheels, 'keys mounted on the numbers on its shaft, a ratchet and pawl device between each key and adjacent wheel, levers having their free ends normally bearing on the shaft and engaging under the keys, and means on the number wheels for actuating the levers, whereby a key is moved one step each time the wheel of next lower value moves ten steps.

5. A calculating machine. comprising a plurality of number-carrying wheels, a shaft supporting the wheels, keys mounted on the shaft, a ratchet device between each key and adjacent wheel, a lever associated with each key and ful-crumed at a point beyond the Wheels and extending across the top of the shaft to normally bear thereon, and each lever having a hook for engaging under the associated key, and means on each wheel for engaging and lifting the associated, lever for lifting the associated key one unit movement for every ten unit movements of the wheel.

6. In a calculating machine, the combination of a number-carrying wheel having eriphery, teeth projecting from the face of the wheel and spaced correspondingly to the numbers on the wheel, said teeth being arranged within a circle, a

key associated with the wheel, a pawl piva member carried by each hold-back pawl and forming a stop for the adjacent key when in zero position.

THOMAS J. WAVRUNEK. 

